On Dec. 8, the King County Wastewater Treatment Division announced their proposed alternatives for the Murray and Barton pump stations to control combined sewer overflows (CSOs).

CSOs occur when heavy rain fall exceeds the capacity of a pump station treatment plant, resulting in a combination of untreated wastewater and stormwater flowing directly into Puget Sound. According to King County, the Barton station averages four overflows a year and the Murray station averages five. Their ultimate goal is to reduce those occurrences to no more than one untreated discharge a year.

“Residents expressed a wide range of opinions and preferences during our public process, and an overwhelming number opposed any major construction inside either Lincoln or Lowman Beach Parks,” said Department of Natural Resources and Parks Director Christie True in a press release. “Those options were not pursued because they posed an unacceptable level of impact to the community. We also had to consider the overall cost and technical feasibility.”

The Barton station, south of Lincoln Park, is slated for the Green Stormwater Infrastructure (GSI) project, a series of rain gardens and swales (a low tract of land for collecting rainwater), “between the sidewalks and streets in the Sunrise Heights and Westwood neighborhoods to reduce overflows from the Barton Pump Station,” according to the press release.

According to the press release, “During heavy rains, the GSI alternative would control CSOs at Barton Pump Station using soils and vegetation to capture and reduce stormwater that would enter the conveyance system. The area’s gentle topography and the connection of street drains to the combined sewer system make the alternative technically feasible.

The County said West Seattle showed support for the GSI solution during public comment sessions and that it falls in line with their, “commitment to energy conservation and sustainability.”

The recommended alternative for Murray Avenue Pump Station is to build a one million gallon storage tank under private property across from Lowman Beach Park. The County said identifying a CSO solution for Murray was more difficult than Barton due to, “the area’s steep terrain and the way in which sewer lines are configured.”

The plan will require King County to purchase six private properties across from the park.

“As a life-long West Seattleite, I am keenly aware of the importance of every home, whether rental or owner-occupied, to the identity and stability of our community,” said County Executive Dow Constantine in the press release. “However, the alternatives all have impacts of their own.”

The county said the Murray proposal, “offers the advantage of a single facility in the immediate vicinity of the existing pump station, which supports reliable operation and efficient maintenance,” in addition to keeping any new construction from happening in Lowman Beach Park.

The next step in making these changes a reality is a Department of Ecology SEPA (State Environmental Policy Act) review, scheduled for early 2011. During that time there will be more opportunity for public comment. Construction of the alternatives is scheduled to begin in 2013.

For more information visit www.kingcounty.gov\csobeachprojects or contact King County Wastewater Treatment Division community services planner Martha Tuttle at 206-684-1207.